Other mistake: When we see the "regulators" riding over the hill on the way to kill Django and Schultz, if you look carefully at the right-center portion of screen, you can see one of the stuntmen fall off his horse and the horse continues to run down the hill without him. To make matters even worse, it appears the stuntman rolls right in front of another horse and gets trampled. (00:41:00)Spencer Crouse
Audio problem: In the scene where Jack Bondurant is loading jars into the back of the truck, Floyd Banner is driven into town and screeches to a halt nearby. Although the tyres screech which is characteristic of tyres stopping suddenly/losing traction on Tarmac or cement, the car is on a loose dirt road.